Honestly, I have never wanted user-definable menu shortcuts on a 90's desktop application either. Each time I saw it, it was a crutch for making a badly designed menu a bit less worse, and things would be much better if the time spent on that feature was simply spent on a better menu.

Very few CAD programs gained something from customized menus (not icons). But this one was also almost always a crutch for fixing bad designs, and those same few programs always gained much more by having a good keyboard based interface.